[This is part two of a three-part series of posts on the rise, principles, and challenges of Green Architecture. The following is excerpted from a longer article on Green Design written for the 2008 Britannica Book of the Year.]

The advances in research and in building techniques achieved by the green-design luminaries mentioned in post one of this series have been compiled into a reliable database of environmental construction methods and sustainable materials—some of which have been in use for thousands of years yet remain the basis for contemporary advances in environmental technology.

The following list includes the essential green-design principles for private residences in the new millennium:

Energy sources. Whenever feasible, build homes and communities that supply their own power; such buildings may operate entirely off the regional power grid, or they may be able to feed excess energy back onto the grid. Wind and solar power are the usual alternatives. The quality of solar collectors and photovoltaic panels improves almost daily; practical considerations for choosing one supplier over another include price, durability, availability, delivery method, technology, and warranty support.

Energy conservation. Weatherize buildings for maximum protection against the loss of warm or cool air. Major chemical companies have developed responsibly manufactured, extremely dependable moisture-resistant insulating materials that do not cause indoor humidity problems. Laminated glass has also been radically improved in recent years; some windows provide the same insulation value as traditional stone, masonry, and wood construction. In regions that experience extreme heat, straw-bale or mud-brick construction—used since ancient times—is a good way to save money and energy.

Reuse of materials. Do the research to find recycled building materials. Although such products were scarce in the early 1990s, today numerous companies, which can be easily located on the Internet, specialize in salvaging refuse from demolition sites.

Safety of materials. Thoroughly research the chemical composition and off-gassing characteristics of all products to be used in construction. The online service of the U.S. Department of Energy is one of the most reliable sources of information on this subject.

Siting. Consider using underground or earth-sheltered architecture, which can be ideal for domestic living. Starting at a depth of about 1.5 m (5 ft) below the surface, the temperature is a constant 52 degrees—which makes the earth itself a dependable source of climate control.

Individual, corporate, and governmental efforts to comply with or enforce LEED standards, engage in recycling at the household and community level, construct smaller and more efficient buildings, and encourage off-the-grid energy supplies are all potentially valuable contributions to a sustainable future. Such efforts alone cannot preserve the global ecosystem, however. On the most basic level, the ultimate success of any globally sanctioned environmental movement will depend as much on its social, psychological, and aesthetic appeal as on its use of advanced technologies.

The environmental movement in the 21st century will meet resistance to the extent that proponents appear to ask populations to scale back the benefits of industrialization. The ultimate success of green architecture is likely to require that advocates achieve a broad-based philosophical accord and provide the same kind of persuasive catalyst for change that the Industrial Revolution offered in the 19th century. This means shaping a truly global (as well as optimistic and persuasive) philosophy of the environment. The architecture profession will have to abandon the past century’s specialization and reliance on technology. Integrative thinking in the building arts can produce a productive checklist of grass-roots-originated, community-oriented, and globally unifying objectives. In the words of Earth Day founder Gaylord Nelson, “The ultimate test of man’s conscience may be his willingness to sacrifice something today for future generations whose words of thanks will not be heard.”